/*
 * (C) Copyright 2000-2010
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
 * Andreas Heppel <aheppel@sysgo.de>

 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

/*
 * 09-18-2001 Andreas Heppel, Sysgo RTS GmbH <aheppel@sysgo.de>
 *
 * It might not be possible in all cases to use 'memcpy()' to copy
 * the environment to NVRAM, as the NVRAM might not be mapped into
 * the memory space. (I.e. this is the case for the BAB750). In those
 * cases it might be possible to access the NVRAM using a different
 * method. For example, the RTC on the BAB750 is accessible in IO
 * space using its address and data registers. To enable usage of
 * NVRAM in those cases I invented the functions 'nvram_read()' and
 * 'nvram_write()', which will be activated upon the configuration
 * #define CONFIG_SYS_NVRAM_ACCESS_ROUTINE. Note, that those functions are
 * strongly dependent on the used HW, and must be redefined for each
 * board that wants to use them.
 */

#include <common.h>
#include <command.h>
#include <environment.h>
#include <linux/stddef.h>
#include <search.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/mman.h>



env_t *env_ptr = NULL;

char * env_name_spec = "persist";

extern uchar default_environment[];

#ifndef SS_DEVICE
#define SS_DEVICE "env.bin"
#endif

static int write_secure_storage(const char* dev,const long offset,const unsigned char* dat,const unsigned int datlen){
	FILE *out;
	int ret = -1;

	out  = fopen ( dev,  "w" );
	if (out == NULL)
		goto ERROR3;

	
    fseek(out, offset, SEEK_SET);

	fwrite(dat, datlen, 1, out);

	ret = 0;
	ERROR1:
	ERROR2:
	fclose ( out );
	ERROR3:
	return ret;
}
static int read_secure_storage(const char* dev,const unsigned char* dat,const unsigned int offset,const unsigned int bytes){
    int ch;
    FILE *in;
    int val = 0;
    char buf[512];
    unsigned i;
    int ret = -1;

    in  = fopen ( dev,  "r" );
    if (in == NULL)
        goto ERROR3;

    fseek(in, offset, SEEK_SET);

    ret=fread((void*)dat, bytes, 1, in);

    ret = 0;
ERROR1:
ERROR2:
    fclose ( in );
ERROR3:
    return ret;	
}

static void *__persist_read(void *dest, const long offset, size_t count){
	if(gd->read)
		return gd->read(dest,offset,count);
	read_secure_storage(SS_DEVICE,dest,offset,count);
	return dest;
}

static void __persist_write(const long offset, const void *src, size_t count){
	if(gd->write)
		gd->write(offset,src,count);
	else
		write_secure_storage(SS_DEVICE,offset,src,count);
}
uchar env_get_char_spec(int index)
{
	uchar c=0;

	__persist_read(&c, CONFIG_ENV_ADDR+index, 1);

	return c;
}

void env_relocate_spec(void)
{
	char buf[CONFIG_ENV_SIZE];

	__persist_read(buf, CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
	env_import(buf, 1);
}

int saveenv(void)
{
	env_t	env_new;
	ssize_t	len;
	char	*res;
	int	rcode = 0;

	res = (char *)&env_new.data;
	len = hexport('\0', &res, ENV_SIZE);
	if (len < 0) {
		printf("Cannot export environment\n");
		return 1;
	}
	env_new.crc = crc32(0, env_new.data, ENV_SIZE);

	__persist_write(CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE);
	return rcode;
}


/*
 * Initialize Environment use
 *
 * We are still running from ROM, so data use is limited
 */
int env_init(void)
{
	ulong crc=0;
	uchar data[ENV_SIZE];
	memset(data,0,ENV_SIZE);
	__persist_read(&crc, CONFIG_ENV_ADDR, sizeof(ulong));
	__persist_read(data, CONFIG_ENV_ADDR+sizeof(ulong), ENV_SIZE);

	if (crc32(0, data, ENV_SIZE) == crc) {
		gd->env_addr  = (ulong)CONFIG_ENV_ADDR + sizeof(long);
		gd->env_valid = 1;
	} else {
		gd->env_addr  = (ulong)&default_environment[0];
		gd->env_valid = 0;
	}
	
	env_relocate_spec();

	
	return (0);
}
